Technical Field
Embodiments of the invention relate generally to visualizing objects within an imaged subject.
Discussion of Art
Imaging systems used by physicians to perform diagnostic analysis and therapeutic procedures produce images by exposing a patient to radiation such as x-rays. Typically, the larger the amount of radiation used during an imaging procedure, the better the image quality of the produced images. Exposure to certain types of radiation, however, can potentially cause unwanted sides effects in the patient. As a result, many imaging systems seek to conserve the total amount of radiation used during an imaging procedure, i.e., the “radiation dose” of the imaging procedure. The radiation dose afforded by an imaging system for a particular imaging procedure is known as the imaging system's efficiency. For example, an imaging system that is more efficient than other imaging systems will have a lower radiation dose while achieving the same and/or better image quality than the other imaging systems for the same imaging procedure.
Many imaging systems seek to reduce the radiation dose of an imaging procedure by allowing a physician to manually adjust the amount of radiation used to generate a series of images during an imaging procedure. For example, many imaging systems typically allow a physician to increase and/or decrease the amount of radiation used to produce images as required, e.g., using a high amount of radiation during parts of an imaging procedure that require high resolution; and using a low amount of radiation when low resolution images, or no images, will suffice. Once an imaging procedure is underway, however, it is often the case that a physician is too preoccupied with other aspects of the imaging procedure to efficiently adjust the amount of radiation as needed.
Accordingly, many imaging systems use automated control loops that adjust the amount of radiation based on noise and average brightness levels measured in the produced images. Systems that measure noise and average brightness levels, however, often fail to identify parts/steps of an imaging procedure where image quality may be reduced and/or increased as the difficulty level, i.e., the need for high quality imagery, of the imaging procedure changes. As a result, many imaging systems often miss opportunities to reduce the radiation dose of an imaging procedure. Moreover, in many imaging systems, the only operating parameter modulated to reduce the radiation dose of a particular imaging procedure is the amount/intensity of radiation used to generate one or more images.
What is needed, therefore, is a system and method for adjusting a radiation dose during imaging of an object within a subject to improve efficiency.